Heat exchangers or radiators of the cross-flow variety are generally formed from a plurality of relatively flat heat exchange plates, each plate having an inlet port at one end and an outlet port at the opposite end joined by a fluid passage or conduit having turbulizer means therein to break up and distribute the fluid flow over the heat exchange surfaces; while a second fluid, such as air passes between the plates in a direction perpendicular to the direction of fluid flow within the plates. Also, a heat exchange plate may be of the multipass type where both the inlet and outlet ports are located at the same end of the plate.
The individual plates are stacked together with the inlets and outlets aligned and are brazed or otherwise sealed together in fluid-tight relation. The top and bottom plates have normally imperforate outer surfaces, except for the inlet and outlet ports, to close the heat exchanger, and suitable fittings are secured to the inlet port and outlet port at the upper and/or lower ends of the stack for attachment to suitable lines communicating with the fluid to be cooled. If, for any reason, a surge tank is required for the heat exchanger or radiator, it is generally isolated therefrom and connected through an externally positioned connection between the heat exchanger core and the tank.
With the advert of higher operating temperatures and pressures of modern automotive cooling systems, especially due to the addition of pollution control equipment on automotive engines requiring higher operating temperatures, a surge or overflow tank is virtually a necessity for proper operation of the cooling system. The present invention, therefore, relates to the use of a surge tank with a heat exchanger or radiator of the cross-flow type, and more particularly to a heat exchanger or radiator having an integral surge tank.
The present invention comprehends the provision of a novel heat exchanger, radiator or evaporator having an integral surge tank to compensate for the volume changes, as a result of temperature variation, of both the heat exchanger and the fluid therein and provide deaeration of the fluid during vehicle operation, including afterboil. This is accomplished by providing a surge tank with a retained air space therein which is not used for heat transfer. As a result, the heat exchanger remains full of fluid at all times which, in turn, increases the efficiency of the heat exchanger.
The present invention also comprehends the provision of a novel stacked plate heat exchanger or a radiator or evaporator of the plate-fin separator variety which has an integral surge tank formed at one end of the assembly. While a stacked plate heat exchanger or plate-fin separator radiator or evaporator normally consists of a plurality of elongated plates connected at their ends to provide aligned inlet and outlet ports forming an inlet passage and an outlet passage connected by a series of fluid passages formed in the plates; the surge tank of the present invention is formed integral with the stacked plates, located beyond one end of the flow passages and connected to the adjacent passage through an embossment formed in the bottom plate of the stack.
The present invention further comprehends the provision of a novel heat exchanger, radiator or evaporator having an integral surge tank that does not require any additional forming or assembly steps other than those required to produce the heat exchanger. This design not only eliminates the manufacturing labor involved in making a surge tank, but also eliminates the mounting and plumbing to a radiator that are required by conventional designs.
Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.